Need help regarding a family issue. How to proceed ?

Hi, im looking for help in a family matter. Iam 23 years old male. I had a really troubled childhood and decided to not live with my parents after i turned 18. I lived with my friend and came to visit parents almost once in a year. after i turned 20 i decided to disown the family so i asked my parents to do so as i did not have a knowledge that i could also go ahead with the process myself. Unfortunately things went bad on personal front and i went into depression and i had to return to my parents house. As i was disowned i asked for their permission to stay and have been living at their residence since 1 and half year. since i have been living with them there have been several times that i have been threatened. They have threatened to frame me into some crime or other and sometimes they just blackmail me. Now they have asked me to leave so im planning to leave but i need them to sign a legal paper which makes me feel more secure that they cannot do any harm. Please Help.